JSFiddle - React, Tailwind, and code Playground
JavaScript
var myString = '{"SecureZoneSubscriptionList": { "EntityId": 51350993, "Subscriptions": [{ "ZoneName": "FACCM Membership", "ZoneId": "6460", "ExpiryDate": "9/5/2014 12:00:00 AM", "SellAccess": true, "CostPerPeriod": "0.1", "CycleType": "" }, ] } }';
var matches = myString.match(/"ExpiryDate":\s?"([^"]*)"/);
console.log(matches);
alert(matches[1]);